GetRecords

Gets data records from a Kinesis data stream's shard.

Specify a shard iterator using the ShardIterator parameter. The shard
iterator specifies the position in the shard from which you want to start reading
data
records sequentially. If there are no records available in the portion of the shard
that
the iterator points to, GetRecords returns an empty list. It might
take multiple calls to get to a portion of the shard that contains records.

You can scale by provisioning multiple shards per stream while considering service
limits (for more information, see Amazon Kinesis Data Streams
Limits in the Amazon Kinesis Data Streams Developer
Guide). Your application should have one thread per shard, each reading
continuously from its stream. To read from a stream continually, call GetRecords in a loop. Use GetShardIterator to get the
shard iterator to specify in the first GetRecords call. GetRecords returns a new shard iterator in
NextShardIterator. Specify the shard iterator returned in
NextShardIterator in subsequent calls to GetRecords.
If the shard has been closed, the shard iterator can't return more data and GetRecords returns null in NextShardIterator.
You can terminate the loop when the shard is closed, or when the shard iterator reaches
the record with the sequence number or other attribute that marks it as the last record
to process.

Each data record can be up to 1 MiB in size, and each shard can read up to 2 MiB
per second. You can ensure that your calls don't exceed the maximum supported size
or
throughput by using the Limit parameter to specify the maximum number of
records that GetRecords can return. Consider your average record size
when determining this limit. The maximum number of records that can be returned per
call
is 10,000.

The size of the data returned by GetRecords varies depending on
the utilization of the shard. The maximum size of data that GetRecords
can return is 10 MiB. If a call returns this amount of data, subsequent calls made
within the next 5 seconds throw ProvisionedThroughputExceededException. If
there is insufficient provisioned throughput on the stream, subsequent calls made
within
the next 1 second throw ProvisionedThroughputExceededException. GetRecords doesn't return any data when it throws an exception. For this
reason, we recommend that you wait 1 second between calls to GetRecords. However, it's possible that the application will get exceptions for longer than
1
second.

To detect whether the application is falling behind in processing, you can use the
MillisBehindLatest response attribute. You can also monitor the stream
using CloudWatch metrics and other mechanisms (see Monitoring in the Amazon
Kinesis Data Streams Developer Guide).

Each Amazon Kinesis record includes a value,
ApproximateArrivalTimestamp, that is set when a stream successfully
receives and stores a record. This is commonly referred to as a server-side time stamp,
whereas a client-side time stamp is set when a data producer creates or sends the
record
to a stream (a data producer is any data source putting data records into a stream,
for
example with PutRecords). The time stamp has millisecond precision.
There are no guarantees about the time stamp accuracy, or that the time stamp is always
increasing. For example, records in a shard or across a stream might have time stamps
that are out of order.

Response Elements

The number of milliseconds the GetRecords response is from the
tip of the stream, indicating how far behind current time the consumer is. A value
of
zero indicates that record processing is caught up, and there are no new records to
process at this moment.

The request was rejected because the specified entity or resource can't be
found.

HTTP Status Code: 400

KMSOptInRequired

The AWS access key ID needs a subscription for the service.

HTTP Status Code: 400

KMSThrottlingException

The request was denied due to request throttling. For more information about throttling,
see Limits in the
AWS Key Management Service Developer Guide.

HTTP Status Code: 400

ProvisionedThroughputExceededException

The request rate for the stream is too high, or the requested data is too large for
the available throughput. Reduce the frequency or size of your requests. For more
information, see Streams Limits in the
Amazon Kinesis Data Streams Developer Guide, and Error Retries and
Exponential Backoff in AWS in the AWS General
Reference.

HTTP Status Code: 400

ResourceNotFoundException

The requested resource could not be found. The stream might not be specified correctly.